Form corner clip and methods for making and using the same

ABSTRACT

A form corner clip and method for making and using the same. A form corner clip is formed having a first portion and a second portion. The first portion is a latch to attach to a projection on a first form panel and the second portion, which is immovably attached to the first portion, has a projection that can be engaged by a latch on the second form panel.

REFERENCE TO PROVISIONAL APPLICATION

This application claims the benefit of the provisional patent application entitled “OUTSIDE CORNER CLIP FOR PLYWOOD CONCRETE FORM PANELS,” filed May 16, 2003, by the applicants of this patent application.

TECHNICAL FIELD

The present invention relates to concrete form systems, and more particularly, to concrete form system corner clips and methods for making and using the same.

BACKGROUND OF THE INVENTION

In the prior art there are many methods for casting poured concrete into the shape of walls, pads, and other such shapes. In most of these methods, flat panels, usually of plywood, are used as the molding elements, or forms, to define the surface of the concrete being cast. Originally, these form panels were custom-made for each concrete forming job, then discarded. Eventually it was seen to be advantageous to make reusable, modular forming panels that could be assembled in a variety of configurations and reused many times.

There are many such modular forming systems in existence. They generally provide a standard means of securing a tie, or tensile rod used to hold opposing form panels against the hydrostatic force of the liquid concrete, and a means of connecting adjacent form panels together into a temporarily monolithic unit.

One such modular system is the widely used “1-⅛″ forming system” made by Symons Corporation, Duraform Ltd., Advance Concrete Forms, and others. The basic modular panel in this system is a 1-⅛″ thick plywood panel, typically 24″ wide by 8 feet high. Spaced at vertical intervals on the outside face of each panel, and spanning the width of the panel, are ¼″×2″ steel bars. These panel bars, typically 4, 5, or 6 per 8-foot panel, serve to reinforce the plywood panel and also provide a secure mounting surface for the features used for securing the ties and connecting the panels.

A notched, pivoting metal latch, attached to one side of each panel bar, is used to secure the tie and connect the panels. On the opposite side of each panel bar there is a metal stud or bolt that the notched latch slips over.

At corners in the foundation walls, the present 1-⅛″ forming systems rely on fabricated metal corners, either hinged or of a fixed angle, to join the plywood form panels at the proper angle and to maintain the correct relationship between inside and outside panels for the attachment of the snap ties. These corners extend the full length of the form panels and are fabricated in a range of configurations, to match the various combinations of form height, number of latches per panel, and corner angle. The most commonly used 90 degree outside corner is referred to as a “zero” or a “1×1” corner, typically constructed of 1″ or 1-⅛″ square structural tubing and arranged so that when attached to the form panels the panels' inside edges will touch. Each fabricated corner of this type must match, in length and in number of latches, the form panels to which it is attached.

FIG. 1 is a perspective view of a commonly used prior art fabricated metal corner connected to two form panels.

Since forming contractors typically maintain a stock of panels of different sizes (eight foot high 6-bar panels and four foot high 3-bar panels, for instance), they must likewise keep on hand a selection of corresponding outside corners. In addition, these corners, because of their narrow proportions, tend to be easily damaged in the rough environment in which they are used. These drawbacks of the present outside corners are overcome in the invention that is the subject of this application.

There are, in the prior art, corner clips for connecting form panels at angles other than 90 degrees. The 45-degree corner clip, for instance, is a commonly used loose clip, often referred to as a “bay window clip.” The clip of the present invention fills the need for a loose clip for the most common corner: the 90-degree corner. The adaptation of loose corner clips for this application has been overlooked until the present invention.

SUMMARY OF THE INVENTION

A strong metal clip, such as that shown in FIG. 3, used at each adjoining panel bar, replaces the burdensome connected assembly of swing latches and studs in the prior art, full-height corner. Each corner clip is fashioned to slip over the attachment stud on one end of the panel bar, and has a second attachment stud to engage the pivoting latch on the adjacent panel. Thus, each clip serves the purpose of securely connecting adjacent form panels at a 90 degree angle without the unnecessary structure of a full-height bar or tube.

A significant advantage of the proposed corner clip is the need to stock only one type of clip for use with any style of form panel. Thus, the same collection of corner clips may be used on eight-foot 4-bar panels, nine-foot 5-bar panels, etc. In addition, a set of corner clips may be fabricated for less than the cost of a corresponding old-style corner. These two advantages greatly reduce the cost to forming contractors of maintaining a stock of parts to create outside corners with all of their form panels.

The present invention fulfills the identical requirements of the present fabricated corners, namely: 1) holding the adjacent form panels on a 90 degree outside corner in the proper position, 2) providing a means to connect the form panels, through the system of ¼″×2″ metal bars, swinging latches, and hex-head studs, sufficient to resist the forces exerted by the liquid concrete during a pour.

In addition, the clip of the present invention has the following advantages over the present fabricated corners: 1) the clip may be mass-produced by high-volume metal stamping techniques, without requiring expensive and error-prone assembly or welding, 2) the small clips are less easily damaged in use, storage, or transport than the long, slender fabricated corners in present use, 3) one set of clips may be used on any size of form panel within the 1-⅛″ forming system, requiring a lower investment in corner hardware to create the same forming capability, 4) the clip can be produced at a lower cost than an equivalent fabricated metal corner.

In accordance with a first aspect, the invention is a corner clip for holding a first form panel edgewise perpendicular to a second form panel. The first form panel has a first inner edge and the second form panel has a second inner edge. The first form panel has a first attachment projection and the second form panel has a first attachment latch. The first inner edge of the first form panel is adjacent an inner form surface and an edge surface of the first form panel and the second inner edge of the second form panel is adjacent an inner form surface and an edge surface of the second form panel.

The corner clip includes a first portion adapted to attach to the first attachment projection, and a second portion immovably attached to the first portion and adapted to be attached to the first attachment latch.

According to a second aspect, the invention is a structure for containing a curable fluid while it cures. The structure includes first and second form panels, and a corner clip. The first form panel has a first inner edge and a first attachment projection. The first inner edge of the first form panel is adjacent an inner form surface and an edge surface of the first form panel.

The second form panel has a second inner edge and a first attachment latch. The second inner edge of the second form panel is adjacent an inner form surface and an edge surface of the second form panel.

The corner clip includes a first portion and a second portion. The first portion is adapted to attach to the first attachment projection, and the second portion is immovably attached to the first portion and adapted to be attached to the first attachment latch.

According to a third aspect, the invention is a method for making a corner clip for holding a first form panel edgewise perpendicular to a second form panel. The first form panel has a first inner edge edgewise perpendicular to a second form panel having a second inner edge. The first form panel also has a first attachment projection. The second form panel has a first attachment latch. The first inner edge of the first form panel is adjacent an inner form surface and an edge surface of the first form panel, and the second inner edge of the second form panel being adjacent an inner form surface and an edge surface of the second form panel.

The method includes the steps of a) forming a first portion of the corner clip adapted to attach to the first attachment projection, and b) forming a second portion of the corner clip that is immovably attached to the first portion and adapted to be attached to the first attachment latch.

According to a fourth aspect, the invention is a method for containing a curable fluid while it cures. The method includes the steps of a) forming a first form panel having a first inner edge and a first attachment projection, the first inner edge of the first form panel being adjacent an inner form surface and an edge surface of the first form panel; and b) forming a second form panel having a second inner edge and a first attachment latch, the second inner edge of the second form panel being adjacent an inner form surface and an edge surface of the second form panel.

The method also includes the steps of c) forming a corner clip including a first portion adapted to attach to the first attachment projection, and a second portion immovably attached to the first portion and adapted to be attached to the first attachment latch; and d) attaching the corner clip to the first and second form panels.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a commonly used prior art fabricated metal corner connected to two form panels.

FIG. 2 is a perspective view of a first embodiment of the inventive corner clip connected to two form panels.

FIG. 3 is a top view of a second embodiment of the inventive corner clip.

FIG. 4 is a top view of a third embodiment of the inventive corner clip connected to two form panels.

FIG. 5 is a top view of a fourth embodiment of the inventive corner clip connected to two form panels.

FIG. 6 is a top view of a fifth embodiment of the inventive corner clip connected to two form panels.

FIG. 7A is a diagram illustrating a first step in the process of forming the first embodiment of the inventive corner clip.

FIG. 7B is a diagram illustrating a second step in the process of forming the first embodiment of the inventive corner clip.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 is a perspective view of a commonly used prior art fabricated metal corner connected to two form panels. The metal corner 100 includes a length of square tubing 102 and an attachment portion 104 that is connected to the square tubing 102. The attachment portion 104 includes first and second plates 106 and 108, which are welded or otherwise permanently fixed to the length of square tubing 102. A portion of the first plate 106 extends outwardly from the square tubing 102 and has an attachment projection in the form of a first stud 110 attached to the outwardly extending portion. The second plate 108 has a second stud 112 attached to it. The longitudinal axes of the first and second studs 110 and 112 are mutually perpendicular. Both of the first and second studs 110 and 112 are respectively attached to the first and second plates 106 and 108 by conventional means, such as a weld or a threaded connection. A first latch 114 is captured on the second stud 112 and rotates about the longitudinal axis of the second stud 112. The first latch 114 has a slot 115 that is adapted to attach to a stud.

The metal corner 100 is used to hold a first form panel 120 and a second form panel 122 so that their respective inner edges 124 and 126 are adjacent and so that they are edgewise perpendicular. (The first and second form panels 120 and 122 are shown in partial view.) The inner edge 124 is adjacent the inner surface 128 and the edge surface 130 of the first form panel 120. The inner edge 126 is adjacent the inner surface 132 and the edge surface 134 of the second form panel 122. The first and second form panels 120 and 122 include the panel bars 136 and 138 over parts of their respective outer surfaces 140 and 142. Typically the majority of the first and second form panels 120 and 122 are made from plywood and the panel bars 136 and 138 are made from steel. The panel bar 136 has an attachment projection in the form of an attached third stud 144 that projects outwardly from the outer surface 140, and the panel bar 138 has an attached fourth stud 146 that projects outwardly from the outer surface 142. The third stud 144 is attached near the edge surface 130 of the first form panel 120, and the fourth stud 146 is attached near the edge surface 134 of the second form panel 122. An attachment latch in the form of a panel bar latch 148 is captured on the fourth stud 146 and rotates about the longitudinal axis of the fourth stud 146. The panel bar latch 148 has a slot 149 that is adapted to attach to a stud.

To hold the first and second form panels 120 and 122 in the desired relative position, the square tubing 102 of the metal corner 100 is first aligned between the edge surfaces 130 and 134 and parallel to the inner edges 124 and 126. While maintaining this alignment of the square tubing 102 between the two form panels, the first latch 114 is rotated until the slot 115 is engaged with the stud 144 and the latch 148 is rotated until the slot 149 is attached to the stud 110.

FIG. 2 is a perspective view of a first embodiment of the inventive corner clip connected to two form panels. The same reference numerals are used in FIG. 2 to describe features already described in FIG. 1. The metal clip 200, which can be formed from a single metal bar, includes a first portion 202 and a second portion 204. Since the metal clip 200 is made from a single piece of material, the second portion 204 is immovably attached to the first portion 202.

The first portion 202 includes a flat length 205 of the metal bar that has a slot 206 formed therein. The slot 206 is adapted to attach to the third stud 144. The second portion 205 is bent away from the form panels 120 and 122 at the outward bend 208 and also toward the form panel 122 at a right angle bend 210. A U-shaped bend 212 having a first leg 214 and a second leg 216 completes the form of the metal clip 200. The U-shape of the metal clip 200 allows the second portion of the metal clip 200 to occupy the space between the edge surfaces 130 and 134. Accordingly, when the metal clip 200 is properly holding the first and second form panels, the extreme 217 of the U-shaped bend 212 makes line contact with the edge surface 134 and the second leg 216 of the U-shaped bend 212 makes surface contact with the edge surface 130.

A stud 218 is attached to the first leg 214 of the U-shaped bend 212 and projects outwardly perpendicular to the plane of the outer surface 142. The stud 218 adapts the second portion of the metal clip 200 to be attached to the second form panel 122.

In use, the metal clip 200 is attached to the first form panel 120 by engaging the slot 206 of the first portion 202 with the third stud 144. Because the metal clip 200 is then making surface contact with the edge surface 130, the metal clip 200 is held stably in position while the slot 149 of the panel bar latch 148 is attached to the stud 218.

FIG. 3 is a top view of a second embodiment of the inventive corner clip. The same reference numerals are used in FIG. 3 to describe features already described in FIGS. 1 and 2. The metal clip 300, which can be formed from a single metal bar, includes a first portion 302 and a second portion 304.

Since the metal clip 300 is made from a single piece of material, the second portion 304 is immovably attached to the first portion 302.

The first portion 302 includes a flat length 205 of the metal bar that has a slot 206 formed therein. The slot 206 is adapted to attach to the third stud 144. When the metal clip 300 is attached to the first and second form panels 120 and 122, it is bent away from the form panels 120 and 122 at the outward bend 208 and also toward the form panel 122 at a right angle bend 210. Two more right angle bends 306 and 308 complete the form of the metal clip 300 and define the legs 310, 312 and 314. The shape of the metal clip 300 allows the second portion of the metal clip 300 to occupy the space between the edge surfaces 130 and 134. Accordingly, when the metal clip 300 is properly holding the first and second form panels, the surface of the leg 312 makes surface contact with the edge surface 134, and the leg 314 makes surface contact with the edge surface 130.

A stud 218 is attached to the leg 310 and projects outwardly perpendicular to the plane of the outer surface 142. The stud 218 adapts the second portion of the metal clip 300 to be attached to the second form panel 122.

In use, the metal clip 300 is attached to the first form panel 120 by engaging the slot 206 of the first portion 302 with the third stud 144. Because the metal clip 300 is then making surface contact with the edge surface 130, the metal clip 300 is held stably in position while the slot 149 of the panel bar latch 148 is attached to the stud 218.

FIG. 4 is a top view of a third embodiment of the inventive corner clip connected to two form panels. The same reference numerals are used in FIG. 4 to describe features already described in FIGS. 1-3. The metal clip 400, which can be formed from a single metal bar, includes a first portion 402 and a second portion 404. Since the metal clip 400 is made from a single piece of material, the second portion 404 is immovably attached to the first portion 402.

The first portion 402 includes a flat length 205 of the metal bar that has a slot 206 formed therein. The slot 206 is adapted to attach to the third stud 144. When the metal clip 400 is attached to the first and second form panels 120 and 122, a louver 406 (which is formed from the middle portion of the flat length 205 by methods and means known to those skilled in the relevant arts) impinges on the end 408 of the panel bar 136. A right angle bend 410 forms the second portion 404 and turns it toward the panel bar 138 of the form panel 122 and aligns the end 412 of the second portion 404 with the end 414 of the panel bar 138. The second portion 404 also has a tab 416 formed from its central portion. The tab 416 extends away from the panel bar 138 and supports the first stud 110 which projects outwardly perpendicular to the plane of the outer surface 142. The stud 110 adapts the second portion of the metal clip 400 to be attached to the second form panel 122.

In use, the metal clip 400 is attached to the first form panel 120 by engaging the slot 206 of the first portion 402 with the third stud 144.

FIG. 5 is a top view of a fourth embodiment of the inventive corner clip connected to two form panels. The same reference numerals are used in FIG. 5 to describe features already described in FIGS. 1-3. The metal clip 500, which can be formed from a single metal bar, includes a first portion 502 and a second portion 504. Since the metal clip 500 is made from a single piece of material, the second portion 504 is immovably attached to the first portion 502.

The first portion 502 includes a flat length 205 of the metal bar that has a slot 206 formed therein. The slot 206 is adapted to attach to the third stud 144. When the metal clip 500 is attached to the first and second form panels 120 and 122, it is bent away from the form panels 120 and 122 at the outward bend 208 and then toward the form panels 120 and 122 at a right angle bend 506. Two more right angle bends 508 and 510 complete the form of the metal clip 500 and define the legs 512, 514 and 516. The leg 514 is formed with shrink flanges to give it greater strength.

The shape of the metal clip 500 allows the second portion of the metal clip 500 to occupy the space between the edge surfaces 130 and 134. Accordingly, when the metal clip 500 is properly holding the first and second form panels, the surface of the leg 512 makes surface contact with the edge surface 130, and the leg 514 makes surface contact with the edge surface 134.

A stud 218 is attached to the leg 516 and projects outwardly perpendicular to the plane of the outer surface 142. The stud 218 adapts the second portion of the metal clip 500 to be attached to the second form panel 122.

In use, the metal clip 500 is attached to the first form panel 120 by engaging the slot 206 of the first portion 502 with the third stud 144. Because the metal clip 500 is then making surface contact with the edge surface 130, the metal clip 500 is held stably in position while the slot 149 of the panel bar latch 148 is attached to the stud 218.

FIG. 6 is a top view of a fifth embodiment of the inventive corner clip connected to two form panels. The same reference numerals are used in FIG. 6 to describe features already described in FIGS. 1-4. The metal clip 600, which can be formed from a single metal bar, includes a first portion 602 and a second portion 604. Since the metal clip 600 is made from a single piece of material, the second portion 604 is immovably attached to the first portion 602.

The first portion 602 includes a flat length 205 of the metal bar that has a slot 206 formed therein. The slot 206 is adapted to attach to the third stud 144. When the metal clip 600 is attached to the first and second form panels 120 and 122, a louver 406 (which is formed from the middle portion of the flat length 205 by methods and means known to those skilled in the relevant arts) impinges on the end 408 of the panel bar 136. A bend 606 bends the metal clip 600 away from the form panel 122 and a right angle bend 608 forms a leg 610 and turns the second portion 604 toward the form panel 122. A further right angle bend 612 and bends the second portion 604 toward the first form panel 120 and immediately adjacent the edge surface 134. The leg 610 also supports the first stud 110 which projects outwardly perpendicular to the plane of the outer surface 142. The stud 110 adapts the second portion of the metal clip 600 to be attached to the second form panel 122.

In use, the metal clip 600 is attached to the first form panel 120 by engaging the slot 206 of the first portion 402 with the third stud 144.

FIG. 7A is a diagram illustrating a first step in the process of forming the first embodiment of the inventive corner clip and FIG. 7B is a diagram illustrating a second step in the process of forming the first embodiment of the inventive corner clip. The process involves a tool 700 and a die 702 (both shown edge-on FIGS. 7A and 7B). The process is applied to a piece 704 whose cross-section is a dimpled U-shape, as shown edge-on in FIGS. 7A and 7B. In the process, the tool 700 is engaged with the piece 704 and both are then forced into the die 702 until the piece 704 bottoms out in the die 702. As can be seen from FIG. 7B, this process creates two of the U-shaped bends 212 in the piece 704. If the depth of the piece 704 is equal to the height of the corner clip 200, cutting the piece 700 in half can form two copies of the corner clip 200. If the piece 704 is an extrusion that is longer than the height of the corner clip 200, several copies of the corner clip 200 can be formed by slicing the piece 704 and separating the U-shaped pieces.

While the foregoing is a detailed description of the preferred embodiment of the invention, there are many alternative embodiments of the invention that would occur to those skilled in the art and which are within the scope of the present invention. Accordingly, the present invention is to be determined by the following claims. 

1. A corner clip for holding a first form panel having a first inner edge edgewise perpendicular to a second form panel having a second inner edge, the first form panel having a first attachment projection and the second form panel having a first attachment latch, the first inner edge of the first form panel being adjacent an inner form surface and an edge surface of the first form panel and the second inner edge of the second form panel being adjacent an inner form surface and an edge surface of the second form panel, the corner clip comprising: a first portion adapted to attach to the first attachment projection; and a second portion immovably attached to the first portion and adapted to be attached to the first attachment latch.
 2. The corner clip of claim 1, wherein the first portion includes a second attachment latch.
 3. The corner clip of claim 1, wherein the first portion includes a corner surface support portion that makes line contact with the edge surface of the first form panel.
 4. The corner clip of claim 1, wherein the second portion includes a second attachment projection adapted to be attached to the first attachment latch.
 5. The corner clip of claim 1, wherein the second portion includes a corner surface support portion that makes surface contact with the edge surfaces of the first and second form panels.
 6. The corner clip of claim 1, wherein the second portion includes a corner surface support portion that makes line contact with the edge surface of the second form panel.
 7. A structure for containing a curable fluid while it cures, the structure comprising: a first form panel having a first inner edge and a first attachment projection, the first inner edge of the first form panel being adjacent an inner form surface and an edge surface of the first form panel; a second form panel having a second inner edge and a first attachment latch, the second inner edge of the second form panel being adjacent an inner form surface and an edge surface of the second form panel; and a corner clip comprising: a first portion adapted to attach to the first attachment projection; and a second portion immovably attached to the first portion and adapted to be attached to the first attachment latch.
 8. The structure of claim 7, wherein the first portion of the corner clip includes a second attachment latch.
 9. The structure of claim 7, wherein the first portion of the corner clip includes a corner surface support portion that makes line contact with the edge surface of the first form panel.
 10. The structure of claim 7, wherein the second portion of the corner clip includes a second attachment projection adapted to be attached to the first attachment latch.
 11. The structure of claim 7, wherein the second portion of the corner clip includes a corner surface support portion that makes surface contact with the edge surfaces of the first and second form panels.
 12. The structure of claim 7, wherein the second portion of the corner clip includes a corner surface support portion that makes line contact with the edge surface of the second form panel.
 13. A method for making a corner clip for holding a first form panel having a first inner edge edgewise perpendicular to a second form panel having a second inner edge, the first form panel having a first attachment projection and the second form panel having a first attachment latch, the first inner edge of the first form panel being adjacent an inner form surface and an edge surface of the first form panel and the second inner edge of the second form panel being adjacent an inner form surface and an edge surface of the second form panel, the method comprising the steps of: a) forming a first portion of the corner clip adapted to attach to the first attachment projection; and b) forming a second portion of the corner clip that is immovably attached to the first portion and adapted to be attached to the first attachment latch.
 14. The method of claim 13, wherein step a) includes forming the first portion of the corner clip from a piece of material, and step b) includes the step of forming the second portion of the corner clip from the same piece of material.
 15. The method of claim 13, wherein the first portion includes a corner surface support portion that makes line contact with the edge surface of the first form panel.
 16. The method of claim 13, wherein the second portion includes a second attachment projection adapted to be attached to the first attachment latch.
 17. The method of claim 13, wherein the second portion includes a corner surface support portion that makes surface contact with the edge surfaces of the first and second form panels.
 18. The method of claim 13, wherein the second portion includes a corner surface support portion that makes line contact with the edge surface of the second form panel.
 19. A method for containing a curable fluid while it cures, the method comprising the steps of: a) forming a first form panel having a first inner edge and a first attachment projection, the first inner edge of the first form panel being adjacent an inner form surface and an edge surface of the first form panel; b) forming a second form panel having a second inner edge and a first attachment latch, the second inner edge of the second form panel being adjacent an inner form surface and an edge surface of the second form panel; c) forming a corner clip including a first portion adapted to attach to the first attachment projection, and a second portion immovably attached to the first portion and adapted to be attached to the first attachment latch; and d) attaching the corner clip to the first and second form panels.
 20. The method of claim 19, wherein step c) includes forming a second attachment latch.
 21. The method of claim 19, wherein step c) includes forming a corner surface support portion that makes line contact with the edge surface of the first form panel.
 22. The method of claim 19, wherein step c) includes forming a second attachment projection adapted to be attached to the first attachment latch.
 23. The method of claim 19, wherein step c) includes forming a corner surface support portion that makes surface contact with the edge surfaces of the first and second form panels.
 24. The method of claim 19, wherein step c) includes forming a corner surface support portion that makes line contact with the edge surface of the second form panel. 